Apparatus for transfer of light liquid



Nov. 2, 1948. w. s. YOUNG APPARATUS FOR TRANSFER OF LIGHT LIQUID Filed Jan. '19, 1946 F/6./. Has;

Inna

INVENTOR.

W/L LIAM s. YOUNG A TTORNEVS Patented Nov. 2, 1948 '2;

APPARATUS FOR TRANSFER OF LIGHT LIQUID William S. Young, Philadelphia,,Pa., assignor to Consolidated Engineering Corporation, Pasadena, Calii., a corporation of California Application January 19, 1946, Serial No. 642,376

12 Claims.

This invention is concerned with the transfer of light liquids from one container to another and provides novel means for such transfer while maintaining a seal between the containers.

In the introduction of samples into analytical apparatus such as mass spectrometers and infrared spectrometers, a liquid to be analyzed should be introduced, preferably in predetermined quantity, without introducing a contaminant, for example air. This has been accomplished heretofore through valves, stop cocks, and the like, but such devices are not entirely satisfactory since the moving parts of valves, cocks, etc. present an opportunity for leakage andlubricants employed to seal the moving parts may contaminate the sample or absorb part of it, thus making itunrepresentative.

. In accordance with my invention such-devices as valves, stop cocks, etc. may be eliminated, anda sample of light liquid introduced into a conduit, say the sampling system of the mass spectrometer or the inlet to a container, through a seal containing no moving parts. This is acc'omplished by attaching to the conduit a seal .composed of a porous member that is pervious to the light liquid to be introduced, but impervious to the heavy liquid which forms a pool covering the porous member; The heavy liquid should be such that the light liquid is insoluble in it and immiscible with it. A sample of the light liquid is placed in a tube of small bore, preferably one of capillary dimensions, having an open end. In the case of a large sample, the tube may be only part of the container. The open end of the tube is inserted into the pool and brought in contact with the surface of the porous member therein. If the pressure in the tube is made higher than that in the conduit, the light liquid will be forced through the tube into the conduit while the heavy liquid, which is displaced only from the place of contact be- .say glass, is preferred Preferably, the open end of the tube is of small exterior cross-section as well as interior crosssection. Thus, the tube may have a relatively heavy wall'tapered to a point at the open end. In order to prevent the light liquid from creeping up the tube out of the pool of heavy liquid, it is desirable topollish th? extreme and o; the

tube, i. e. across its section, and better still to polish the tapered portion of the outside wall of the tube adjacent the open end. Thus, the wallspof the tube adjacent the open end may be thinned gradually toward the open end to provide apoint, the open end itself and theginterior tube'ivall adjacent thereto being polished;w

If the tube is of capillary bor, a sample of liquid-to be introduced through theseahylill rise naturally into the tube if the open endis inserted'into abody of the light liquid. However, in some instances it may be desirable to ,provide other-means for sucking liquid into the open end of the-tube, for example, an expansible bulbconnectedto the tube at its other end'or a plunger type pump or syringe likewise connected to the tube at-its other end.

As-indicated above, the tube may be simply an exitirom a larger vessel when a sample of considerable size is to be introduced. However, in the-case of sample for analysis in aan ass spectrometer or an infra-red spectrometer, a long capillary tube ordinarily is itself a sufficient contain" for such samples are relativelysmall. In suchcase, the tube may have marks orgradnations} along its length and thus vwill serve-as an index-of the quantity of liquid passed through the sea-linto the conduit.

The pressure diilereutial'required; to force the jthroughthe tip of the micro-burette of Fig.

taken along the line 2-2;

Fig. 3-hshows the micro-buretteoi Fig. 1 equippedwith a suction bulb and placed in a mercury well;

Fig. ris an elevation partly in section illustrating two other practices oi the invention:

and

Fig.5 illustrates the application of the invention to a weighing bottle for accurately determining the weights of ingredients of a sample .compounded in a sealed container.

Referring. to Fig. 1, it will be observed that the micro-burette Ill comprises a thickwalled glass- I tube haying a small bore H, preferably.;g f. capillarygdimensions. The burette has graduae tions along its length for measurementpurposes and may be made conveniently from a piece'oi thermometer tubing. The upper endof the tube has aILiIlVBlftt-Edf conical seat; 'IZ' adaptledtora tightly fitting connection with a hypodermic syringe or the like.

tapered to a very thin-walled-section' at theex!- treme end of the tube. polished transversely to the bore, and the conical surface M is likewise polished; This polish is desirable, although not essential, inforder. toprevent creep of the light liquid upwardly in the seal.

Referring to Fig. 3, the micro-burette H! of. Fig. 1 is equipped with an expansible bulb l5 of'rubbar or the like fastened over its upper end. The burette stands vertically. with its pointed Tower end in contact with a porous disk. It. This disk is pervious to a light liquid, say a light hydrocarbon fraction, but is-impervious tea-pool H of mercury which overlies the porous disk in a well f8" of generally frustoconical' section;

The disk preferably is made by sinteringtogether fine particles of glass and issealed into the sides" of the well which projects below and joins a tubular conduit Id.

In the operation of the apparatus of'Fig. 3, a sample oflight' hydrocarbon or the like to be analyzed is suckedi'nt'o' themicro-burette from a supply of the liquidih a testtube or the like. If the micro-bur'ette is of capillary bore, the liquid will riseby itself. Butthe'operation can be aided by means of suction obtainedwi'th the bulb. When the sample is in" the burette; the latter is wiped clean and introduced point down into the pool of mercury. Preferably; the-pointis-"introduced fromthe side, with themicro-burette held at an oblique angle with the-horizontal. When the burettecomes" in contact with the porous disk, it is straightenedup to a vertical position.

soon as the vertical 'pesit'ion is obtained, assuming' thecorrect porosity to be present atthe zone of contact between theburette and the porous disk, the sample willbe sucked out of the buret't'e through the disk into the conduit fs 'by meansof'sueti'on created in the conduit-by vacuum pump [93A or the like. During the tran'sfer, the mercury in the well seals the juncture.

Fig. 4 illustrates two uses of a micro-bur'ette constructed in accordance with the principles of the invention. Thus, the micro-buretteis of capillary bore and. isprovided with the pointed end described hereinbe'fore. Such a burette is filled with a sample of light liquid to be transferred and after the point has been wiped clean,

it is immersedas describedin the case of the main conduit 26 to which suction is appliedby means of pump 26A.

By means of graduations (not shown onthe micro-burette 20' but indicated on the microburette of Fig; 1 the amount of sample introduced is controlled. Inall c'asesycareshouldbe taken to see that the full liquid sample in=the microgburette i's'not pulled through-the seal since air or other gas; will inevitably follow and'c'on- V taminate'the sample! In other words, contact between the point of the micro-'burette and the porous disk should be broken after only a portion of the contents of' the-micro-burette has been This extreme end I3; is

The lower end of the tube is pointed in substantially conical shape and sucked in. If the bore of the micro-burette is ruamu ummm in size;- the amount of sample introducedcan be measured directly by means of the graduations.

Another micro-burette 21 is shown at the right of Figs. It has 180 curved portion 28 (or hook) at its lower end which has its point 29 in contact with another porous disk 30 which forms the lower wall of achamber 3| that is connected to the suction conduit 26. If the bore of this microburette is of capillary dimensions, a sample can be introduced merely by placing the point of the micro-burette in the container of the sample. If the bore is larger than capillary dimensions or if additional force to suck in the sample is desired, a hypodermic syringe 32 (comprising a simple cyli'nd'er33 and aplunger 34') may be used. This hypodermic syringe has a nipple 35 which fits tightly in asocket 36 in the top of the microhurette. This socket may be similar to the socket I 2 the micro-burette of Fig. l.

The introduction of the sample. from the micro-burette 21 isaccomplished' in the same way as in the previous: cases, except that the sample issucked: upwardly into the conduit system 26 through the disk.

The apparatus of Fig. 5 is useful for compounding samples from known amounts of several light liquids. It employs a capillary pipette W having an expansible bulbt'li. say a medicine dropper bulb, at its enlarged. upper end. As shown in the figure, this projects downwardly intoa-welli supportedon a tripod 43. The well contains a pool of mercury 44 and its bottom comprises a rubber ring. 45;. in the. central opening" of which is disposed a small. sample tube 46. Fig. 5, this sample tube is shown closed at its lower end and is sealed at its upper end by a porous disk 41 that is pervious to a light liquid t'o be' transferred but impervious to the mercury.

In the operation of the apparatus of Fig. 5, the lower end of the container 46 is originally open and it is evacuated by means of a vacuum connection- (not shown) and sealed off, as shown,

' about 20 mm. from the sintered disk, this operation being conducted with the tube in place and with the sintered disk underneath the mercury pool.

The weight of the complete assembly, minus the capillary pipette, should be 10 to 25 grams, depending upon the amount of mercury in the well.

A small amount of liquid to be introduced into the weighing bottle 46 is drawn up into the capill'ary pipette" and the tip of its capillary tube is then put under the mercury to touch the sintered disk until the desired amount of the sample has been sucked through, due to the vacuum in the weighing bottle.

The weighing bottle should be tared on a micro-balance and weighed after each component is added. After all the components are blended, assuming that a blend is to be made in the weighing bottle, the weighing bottle is partly immersed in liquid nitrogen to condense the hydrocarbon vapors and distill out any impurities still in the sintered disk.

The bottle should be warmed and chilled sev eral times in order to assure thorough mixing of the components. Thereafter, the mercury cup is removed to allow air to suck in and the sintered disk is cut elf of the weighing bottle.

The blend may then be removed from the weighing bottle with a fine capillary needle and inserted intothe sampling system of a mass spectrometer or the like through a sintered disk as already described.

It will be apparent that the apparatus of the invention provides a simple and reliable procedure for introducing a sample into an analytical apparatus without contamination from the outside atmosphere,

If desired, of course, the capillary tube can be topped by a large container for the liquid sample, although ordinarily the capacity of the microburette itself is sufficient.

All of the apparatus may be made of glass, although it may be desirable to make the large well 2 in Fig. 4 of somewhat less fragile material.

Suitable sintered disks for use in constructing the apparatus may be purchased as commercial mm. immersion filters of fine porosity.

The micro-burette is conveniently made from thermometer tubing. Such tubing may be obtained with an internal bore so small that it delivers only l.5 10- ml. per cm. length.

I claim:

1. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a porous member communicating with the conduit and covered by the pool, the member bein pervious to the light liquid but impervious to the heavy liquid, a second container for the light liquid to be transferred consisting of a tube of small bore having an open end for contacting the portion of the porous member covered by the pool, and means for producing a pressure differential between the second container and the conduit to induce flow of the light liquid from the second container to the conduit through the tube and the porous member when the latter two are in contact with each other.

2. Apparatus according to claim 1 in which the heavy liquid is mercury.

3. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a porous member communicating with the conduit and covered by the pool, the member being pervious to the light liquid but impervious to the heavy liquid, a vessel for the light liquid to be transferred consisting of a tube of capillary bore having an open end for contacting the portion of the porous member covered by the pool, and means for producing a pressiu'e dififerential between the vessel and the conduit to induce flow of the light liquid from the vessel to the conduit through the tube and the porous memher when the latter two are in contact with each other.

4. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a, porous member communicating with the conduit and covered by the pool, the member being pervious to the light liquid but impervious to the heavy liquid, a tube of small bore from which the light liquid is transferred and having an open pointed end for contacting the portion of the porous member covered by the pool, and means for producing a pressure differential between the tube and the conduit to induce flow of the light liquid from the tub-e to the conduit through the porous member when the tube an}? the porous member are in contact With each ot er.

5. Apparatus according to claim 4 in which the extreme open end of the tube is polished.

6. Apparatus according to claim 4 in which the tapered exterior wall of the tube adjacent the tube is polished.

7. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a porous member communicating with the conduit and covered by the pool, the member being pervious to the light liquid but impervious to the heavy liquid, a tube of small bore from which the light liquid is transferred and having an open end for contacting the portion of the porous member covered by the pool, the walls of the tube adjacent the open end being thinned gradually toward the open end to provide a point, the open end and the exterior tube wall adjacent thereto being polished, and means for producing a pressure diiferential between the tube and the conduit to induce flow of the light liquid from the tube to the conduit through the porous member when the tube and the porous member are in contact with each other.

8. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a porous member composed of siliceous particles sintered together communicating with the conduit and covered by the pool, the member being pervious to the light liquid but impervious to the heavy liquid, 2. tube of small bore from which the light liquid is transferred and having an open end for contacting the portion of the porous member covered by the pool, and means for producin a pressure differential between the tube and the conduit to induce flow of the light liquid from the tube to the conduit through the porous member when the tube and the porous member are in contact with each other.

9. Apparatus according to claim 8 in which the porous member is a sintered glass disk.

10. In apparatus for transferring a light liquid, the combination which comprises a conduit, a container, a pool of heavy liquid that is substantially immiscible with the light liquid disposed in the container, a porous member communicating with the conduit and covered by the. pool, the member being pervious to the light liquid but impervious to the heavy liquid, a tube of small bore from which the light liquid is transferred having an open end for contacting the portion of the porous member covered by the pool, means for sucking the light liquid into the open end of the tube, and means for producing a pressure differential between the tube and the conduit to induce flow of the light liquid from the tube to the conduit through the porous member.

11. Apparatus according to claim 10 provided with an expansible bulb connected to the tube at its other end.

12. Apparatus according to claim 10 provided with a plunger-type pump connected to the tube at its other end.

WILLIAM S. YOUNG.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,770,012 Randall July 8, 1930 2,125,910 Gardner Aug. 9, 1938 

